These prehistoric predators lived through four mass extinction events and survived what the dinosaurs couldn’t, but sadly overfishing may see these fearsome fish wiped out for good
Sharks have been swimming in our oceans for 450 million years. These fearsome fish have developed an excellent set of skills to take down their target with ease. Sharks are able to smell prey from a great distance and as their nostrils are solely for smelling, their olfactory system is highly specialised. It has been claimed that a shark can smell a single drop of blood in an Olympic-sized swimming pool, but it turns out this may have been fuelled by our fear of sharks rather than by fact. Scientists tested five coastal shark species and found their sense of smell was no better than any other fish. Out of more than 400 shark species, one third of open ocean species are endangered. With pollution rife, trawlers everywhere, and movies such as Jaws still popular, it seems as though sharks have been persecuted as a result. Many people have a fear of sharks, but much in the same way people are frightened of spiders that can’t hurt us, sharks pose little danger either. In 2015 there were just 98 unprovoked shark attacks worldwide. Very few of these were fatal and in some cases the sharks were just ‘sample biting’. When the shark realises the human isn’t a suitable meal, they release them. It is possibly an unfounded fear of these creatures that has hampered conservation efforts and fund-raising attempts. Perhaps it’s time they received a PR makeover.
Curtains of death
Gillnets are nets which are set vertically, perpendicular to the ocean floor. There are a wide variety of nets with different sized mesh to trap different species of fish. The holes are just large enough for fish to swim partly through, but not large enough to fit their body through and they get caught by the gills. Gillnetting is an effective means of fishing for species that live near the ocean floor. Sadly, fish we are used to eating and seeing in the supermarkets everyday such as cod, tuna, sea bass and halibut are all caught this way. But it is difficult to only target one species with this method, and many others inevitably get entangled. Sharks, turtles, and dolphins all fall victim. It is little wonder why these nets have been referred to as ‘curtains of death’. Regulations do exist and have been made a large part of the commercial fishing industry in a bid to reduce the amount of fish needlessly killed. But where there is fishing, there is bycatch. However, there are many artisanal and even small-scale fisheries working outside of the regulations. For almost all of the world’s endangered and vulnerable shark species, gill nets are mentioned by the IUCN as a cause for concern and a top priority due to the staggering number of sharks caught up in them and pulled out of the oceans.
Around 200 sharks lose their life every minute
The main causes of increased shark mortality come from a very high demand for shark fin soup, overfishing, and incidental trapping with nets as bycatch. Sharks struggle to recover from intense hunting pressure because of their life history. Females have a low productivity, meaning they produce small litters; these young sharks then have slow growth rates and reach a sexual maturity at a late stage. A slow life cycle means they are less able to compensate for over fishing and unable to bounce back as a population when large numbers are killed. Although many people are now aware of the dangers shark fin soup poses to the species and are more environmentally aware, particularly in the west, there is still a demand for shark products. In China, shark fins are prepared as a soup or a stew and are said to prevent cancer and heart disease, increase appetite and be beneficial to the skin but rigorous scientific testing of these claims has yet to offer any hard evidence.
It is estimated that 11,417 sharks are killed every hour by finning alone. This doesn’t even include sharks killed as bycatch, and a shocking 100 million sharks are killed every year. It sounds a lot, but it gets worse – this is just the conservative ‘best case scenario’ estimate. It could be as many as 273 million. Sharks are an incredibly important part of their ecosystem and act as an indicator of how healthy the ocean is. In short, happy oceans have healthy sharks swimming in them. They are so vital due to their status as an apex predator. Sharks are fish at the top of the food chain, controlling the populations below them and keeping everything in balance, by feeding on the animals below them on the chain.
What state are shark populations in currently?
Scientists estimate that approximately one quarter of shark and ray species are threatened with extinction and require immediate conservation action. This includes some of the better-known species like the great white, great hammerhead and whale shark but also includes many less charismatic but nevertheless valuable species.
This estimate is based on the IUCN Red List, which in 2013 found that 181 out of the 1038 species of sharks and rays assessed fell into one of the three “threatened” categories, including 20 species classified as Critically Endangered. Almost half (472 species), however, are classed as Data Deficient, meaning that we just don’t know enough about the populations to assess their status.
Can you tell us more about the work and projects you are involved in?
We are involved in various wildlife protection, fisheries policy, and responsible trade projects, working with partners around the world to advocate for changes that will safeguard sharks. Our fisheries action is currently spearheaded by our ‘No Limits?’ campaign, which is targeting an end to uncontrolled shark fishing for ‘No Limits?’ species, including the blue and shortfin mako sharks.
Another of our biggest projects, the Great Eggcase Hunt, encourages everyone to explore their local beaches, to search for and submit records of the eggcases from local sharks and rays, building a valuable knowledge base.
What successes have there been so far?
There have been many, from the landmark protection of the basking shark in the UK in the late 1990s to an International Plan of Action for sharks in 1999. In 2013, seven commercially exploited species of sharks and ray were CITES listed, restricting trade across the world, and in the same year the EU Finning Regulation set the international standard for a move away from the practice of finning at sea. But there is still much to be done: We need more science to assess species and develop conservation plans; we need more policy change to set the agenda; we need a shift to sustainable shark fisheries coupled with a responsible global trade in shark products.
Sadly, sharks are notoriously unpopular – how can we change people’s minds?
I don’t think people need to like sharks to appreciate the importance of not driving their populations to extinction. We just need, as a society, to make better decisions to safeguard the future of our wildlife, and those that do value wildlife to be vocal and active.
What are the main threats facing sharks and how can we overcome them?
The biggest current threat to sharks is overfishing. Not shark fishing per se but uncontrolled and unmanaged shark fishing. We have to get a control on shark fishing, push for science-based management, for sustainable fisheries and, take steps to reduce the trade in unsustainable products.Shark conservation is a global issue which requires collaboration. The Shark Trust published a comprehensive 10-year plan as part of a global partnership with WWF, IUCN Shark Specialist Group, Shark Advocates International, TRAFFIC and WCS. There is hope if we act quickly and decisively to protect threatened species, manage fisheries, reform trade and tackle demand for shark products.
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